Typically, an electronic fuel injection system, EFI, of a four-stroke combustion engine has an air throttle body for controlling the amount of air flowing through an engine head intake valve and into the combustion chamber of the engine block. At least one fuel injector of the EFI injects fuel directly into the air throttle body, or alternatively, into the piston cylinder to mix with the incoming air flowing through the throttle body. A spark plug or ignition system then ignites the resultant fuel-and-air mixture within the combustion chamber. The operation and sequential timing of each one of these components is dictated by a variety of engine operating parameters thus requiring various sensors which input into an electronic control unit, ECU, of the EFI system for processing in accordance with software instructions of a microprocessor of the ECU which then outputs signals to perform numerous functions.
The sensors typically include an air temperature sensor, an engine speed sensor, an engine temperature sensor, a pressure sensor, an air mass flow rate sensor and a throttle position sensor all disposed at various locations around the engine. These sensors provide input signals to the ECU which in turn provides output signals which control numerous drivers or power transistors of various components of the EFI system such as fuel injectors, an ignition coil, and a fuel pump. The power transistors, when energized by the output signals of the microprocessor generate heat and thus must be cooled and/or remotely located to avoid damaging the microprocessor.
Manufacturing of known EFI systems is complex, and requires various wiring harnesses, connectors and associated support structures routed or located about the engine to the appropriate sensors and components generally scattered throughout the engine vicinity. The overall system is thus bulky or cumbersome and generally hampers engine maintenance and increases cost. Moreover, excessive electrical connections located about the engine can lead to continuity and system failures caused by debris contamination. Moreover, poor heat management can be damaging to electronic components such as the microprocessor or printed circuit boards of the ECU, thus the ECU typically is located some distance away from the heat dissipating engine and the drivers spaced considerably away from the microprocessor. This contributes toward poor packaging of the engine, EFI system components and/or the entire product application.